1. Field of the Invention
The present invention relates, in general, to a gear train in a multistage transmission mounted in vehicles, and more particularly, to a structure of a gear train in a transmission for vehicles that is capable of having nine forward speeds and one reverse speed.
2. Description of Related Art
Conventionally, a transmission with nine speeds or more that is developed for mounting in vehicles generally has four or more sets of planetary gears, as disclosed in US2009-0197733A and JP2006-349153A, in order to implement a multistage transmission.
However, if using multiple sets of planetary gears as such, the volume or entire length of the transmission tends to be increased so that adaptability to different vehicles is reduced. In addition, since the set of planetary gears naturally has lesser power transmission efficiency than that of gear trains in which gears are simply circumscribed or inscribed, it is disadvantageous in the context of power transmission efficiency.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.